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This article was published in 1951
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
Mineral Imbalance in Wethers
J.C. Beardwood, B.V.Sc., Inspector of Stock, Bathurst, and D.M. Hellwig, Veterinary Student.
Although various types and various degrees of mineral imbalance are common in ewes, this condition is rare in wethers in the field. Very few cases have been recorded, though Franklin (1943) has pointed out that "if conditions are suitable, hypocalcaemia is not confined to in-lamb ewes, or to ewes with lambs at foot, but may occur in any class of sheep and at any time of the year"; while Jones (1945) has described an outbreak of Transit Tetany in a consignment of mixed sex sucker lambs, with blood serum analyses showing low calcium.
About mid-January, 1931, an owner in this District purchased 175 Merino wethers at a local saleyards. These sheep were in particularly good order and had been brought to that condition on an area of comparatively "soft" country about 20 miles from the selling centre involved.
In quite hot weather the sheep were driven to the saleyards in something less than two days; held there without feed overnight; in the yards the whole of the next (the selling) day; and retained in the yards again without feed, on the night following the sale. The next morning they were headed towards the new owner's property, and this being along the road to their former holding, as well as some bustling by fairly heavy traffic, no doubt contributed to the fact that they practically raced for almost seven miles; and arrived at the end of that stage with many "tongueing" and obviously in distress.
The following morning one was dead; with five (5) recumbent and apparently on the point of death. During that day the mob was paddocked and rested on good feed; and moved some three miles to a reserve, where they were seen by us on the next morning. It was stated then that no further cases had occurred. Two of the five affected apparently had recovered sufficiently to regain their feet, but had been left in the "resting" paddock. The remaining three had been taken to the reserve in a vehicle. These appeared to be in extremis and had lost all normal reflexes, A noticeable, though not marked, muscular twitching was present periodically.
It was considered that had the mob consisted of in-lamb ewes in any stage of pregnancy, and been subjected to such treatment over three or four days, a diagnosis of mineral imbalance would have been made forthwith; and almost automatically. The sex in this case did cause a short period of doubt.
In view particularly of the muscle twitching, treatment was of the "shotgun" variety; the initial dose consisting of 80 mls. of a combined 20% Calcium borogluconate and 10% Magnesium sulphate solution. This was given subcutaneously to each of the three sick sheep; which at the time were recumbent in the normal position and displaying no interest at all in life. Some notes on the various stages towards recovery may be of interest:—
Within 20 minutes one sheep showed twitching of the ears due to fly worry and endeavoured to move when approached. The other animals being still comatose, were given a further dose of 20 mls. each.
After 45 minutes all three animals showed an improved alertness about the head and neck; and at that time they were carried to a creek, where they drank readily and easily. Following this the respirations, which had been rapid and shallow, returned to normal almost immediately.
Approximately 75 minutes after treatment one animal endeavoured to get up, but when placed on its feet it staggered a few steps only; showing the same leg weakness as that exhibited by a sheep which has been "cast" for any length of time.
The sheep were last observed by one of us (D.M.H.) 90 minutes after treatment; when it was noticed that one animal was starting to nibble the grass where it was lying and, except for the leg weakness, the other two appeared to be resting normally.
The owner advised subsequently that when the mob was started on the road on the morning following treatment the affected sheep had difficulty in travelling, but that by lunch-time recovery apparently was complete.
In all probability recovery would have been much more rapid had the treatment been given intravenously; but intravenous injection in the sheep scarcely is practicable so far as the average sheep-owner is concerned.
References
- Franklin, M. C., (1943)—Year Book. Inst. Inspectors of Stock, N.S.W. 1943
- Jones, T. R., (1945)—Year Book. Inst. Inspectors of Stock. N.S.W. 1945